It is well known that pipe's, and pipe-shaped objects are routinely used for transporting fluids both above and underground. For example, oil refineries use a vast array of above ground pipes, while underground pipes transport municipal water supplies, irrigation water, drainage water, etc. Above ground pipes may be readily joined together by well known methods including threaded mechanical connections, welding, bonding etc. However, joining underground pipes together necessarily requires substantial labor, risks and costs. (For purposes herein, the words “pipe” and “pipes” are to include all forms of fluid transporting structures, including straight pipe sections, cylindrical pipes, couplings, fittings, joints, etc.)
For example, in transporting irrigation water to and drainage water away from agricultural sites, it is common that a mechanized trenching machine will form a narrow, deep trench in the soil. The depth of the trench may be a function of a “frost-line”, if the water is to pass through the pipe during the winter months. Such trenches may run as deep as four feet or more. If freezing is not a concern, the trenches will still need to be at least two feet to minimize any possible damage to the underground pipe by activity above the pipe. Sections of straight pipe are typically laid in the trench, and then two sections are joined together.
Smooth-wall irrigation water pipe may be made of a type of polymer compound that is joined by sliding an open end of the pipe into a larger receiving end of a coupler. Typically a compression O-ring type of seal is secured within the receiving end of the coupler to provide a fluid seal. The adjacent section of straight pipe is then inserted into an opposed receiving end of the coupler. Some such pipes may simply be joined by forcing a narrow male-end into a wider female-end of an adjacent pipe, using an O-ring seal or solvent bond to seal the pipes together. Corrugated pipe, such as shown schematically in FIG. 4, that is frequently used to transport underground drainage water, may be joined in a similar manner to that described above, using corrugated couplers or male-end female-end insertions, O-ring seals, etc.
When such smooth or corrugated pipe sections are at the bottom of trenches, securing two sections of pipe together requires a laborer to either stand in or reach into the trench and then use manual force to join the two pipe sections together. For a twenty-foot or longer section of pipe, adequate joining force frequently requires two or more laborers using manual effort to force the pipe sections together. Not only does this require significant labor cost in terms of labor hours, but it also gives rise to substantial risks of disrupting the trench by cave-ins of trench walls. Additionally, soil particles may accumulate adjacent open pipe ends as they are forced together so that some such soil particles may enter and remain in the open pipes, causing further costs in purging contaminants from the joined pipe sections. Where such trenches are below a frost-line of for example four feet, substantial costs are incurred to make an entire trench sufficiently wide to facilitate manual labor within the trench that is necessary to join sections of pipe together.
Known efforts to join pipes in confined working areas typically include an operating lever connected to a chain or cable. The chain is wrapped around one end and connected to the lever that is secured to the other or mating end. The lever then is moved to draw the chain and pipe secured thereto into the mating end. An example of a pipe joining tool appropriate for confined working areas is shown in U.S. Pat. No. 4,501,055 that issued on Feb. 26, 1985 to George. The apparatus disclosed in George includes a first pipe engaging member having a C-shaped clamp secured in abutment with a collar on a first pipe section and handle with a winch and pulleys secured to the handle. A cable secured to the winch engages an adjoining second pipe section, and the winch is wound manually to draw the second pipe section into the first pipe section. A more recent pipe joining tool including an elongate handle and a Y-shaped pipe-collar engaging clamp end is disclosed in U.S. Design Patent No. Des. 327,205 that issued on Jun. 23, 1992 to Jones. A chain is secured above the Y-shaped clamp end for pulling a second pipe toward the first pipe to which the clamp end is secured upon pivoting of the handle away from the second pipe. A rigid strut may replace the chain and impact the second pipe to decouple joined pipes upon pivoting of the handle toward the second pipe.
Such known pipe joining tools for working in confined work spaces such as deep trenches, however, still require complicated mechanisms that are susceptible to breaking, that are costly, and that also require manual application of pipe engaging chains, cables, engaging clamps, securing tools, etc. This gives rise to further risks of cave-ins of trenches, contamination of open pipe ends, and breakage of the tools.
Consequently there is a need for an efficient apparatus and method for joining pipes together.